Wednesday, December 16, 2020

Two Postage Stamps Honoring Maria Gaetana Agnesi

In May 2018, I shared about some of the events being held in honor of Maria Gaetana Agnesi's 300th birthday.  But it wasn't until recently that I learned of additional events commemorating the anniversary: two postage stamps were issued to honor Maria, one by the Italian government and the other by the Vatican.

The stamp issued by the Italian government is one of a set of four celebrating “Italian Female Genius." Agnesi's stamp includes a graph of the "witch of Agnesi" curve named for her. She didn't invent the curve, and the name was the result of a mistranslation. See this post to read more about that.


According to, a website devoted to information about Agnesi, the Vatican issued an Agnesi stamp to recognize her as an "outstanding mathematician and impassioned Catholic." The Witch of Agnesi website was established by California State University mathematics professor Shirley Gray, a long-time advocate for recognizing Agnesi's contributions to mathematics. The Vatican stamp depicts Maria in prayer, but it also includes the witch of Agnesi curve on a sheet of paper lying on the floor beside her. 


I'm thrilled to see Maria Gaetana Agnesi honored in this way--it was long overdue!

Friday, October 16, 2020

Maria Gaetana Agnesi Biography on MacTutor Site

There's a great deal of misinformation about Maria Gaetana Agnesi online. One of the reasons I created this site was to point out some of those errors. Today, though, I'd like to share a website that sticks to the facts: the MacTutor History of Mathematics Archive. The site is hosted by the School of Mathematics and Statistics at the University of St Andrews, Scotland. I was pleased to discover that the MacTutor biography of Maria Gaetana Agnesi is based on information from reputable sources, and it includes a list of those sources.

Here's the portrait of Maria included in the MacTutor bio (which is in the public domain):

I commend Edmund Robertson and John O'Connor, the creators of MacTutor, for a job well done!

Friday, September 18, 2020

Celebrating the Novel Playing by Heart, Inspired by the Agnesi Sisters

Monday, Sept. 30, 2020, will mark the third anniversary of the original release of my novel Playing by Heart, which was inspired by the lives of Maria Gaetana Agnesi and her sister, Maria Teresa Agnesi. To celebrate, I'm hosting a book giveaway Sept. 9 through Sept. 30, 2020. You can enter on the blog page of my website.

 If you're not familiar with the novel, here's a brief summary:
     Emilia Salvini dreams of marrying a man who loves music as she does. But in 18th-century Milan, being the 'second sister' means she'll likely be sent to a convent instead. Emilia's only hope is to prove her musical talents crucial to her father's quest for nobility. First, though, she must win over her music tutor, who disdains her simply for being a girl. Too late, Emilia realizes that her success could threaten not only her dreams but her sister's very life.

I incorporated a number of real-life events into the novel, which I explain in the book's Author's Note. And I did extensive research to find details that would help bring the story to life. I feel rewarded for my hard work whenever readers or reviewers comment on the book's details, as the Booklist reviewer did: “Martino’s romantic read features lovable characters and is vibrant in setting and detail.… The book is filled with rich depictions of houses and clothing, allowing readers to clearly picture the historical settings of both Milan and the countryside.” 

The novel has also received some lovely awards. You can read more about Playing by Heart on my website

Saturday, May 16, 2020

Good News for Maria Gaetana Agnesi's 302nd Birthday!

Let's year, I discovered that The Family Coppola has created a brandy called Agnesi 1799 in honor of Maria Gaetana Agnesi. The brandy is part of their line of "Great Women Spirits." I'm happy to report that the company updated their website information about Maria in response to my feedback regarding the inaccuracies there. The info isn't perfect, but it's much better!

So let's toast Maria on the anniversary of her birth as well as the Great Women Spirits marketing staff. Salute!

Thursday, May 16, 2019

Let's Drink to Maria Gaetana Agnesi's 301st Birthday!

As I continue my research on the life of Maria Gaetana Agnesi, today I was surprised to discover that there is now an alcoholic drink named in her honor:

According to an article in Sonoma Magazine, The Family Coppola now has a line of "Great Women Spirits" named for several historic women. The spirits include a brandy that, according to the article, "commemorates Maria Gaetana Agnesi, the first woman to serve as a mathematics professor at a university." Called "Agnesi 1799," the bottle bears a portrait of Maria against the backdrop of the curve of The Witch of Agnesi. The number 1799 commemorates the year of her death.

Sadly, the article perpetuates one of the myths associated with Maria: that she was a mathematics professor. Pope Benedict XIV did indeed offer her a math professorship at the University of Bologna, but she turned it down and never served there. The Family Coppola website repeats this fallacy on the brandy's page. The brandy label itself, described on the bottom of the page, indicates that she was the "theorist of the Witch of Agnesi curve." However, as I discussed in my last post, this is a myth. I plan to contact the company about these errors. I'll let you know if they respond. 

Meanwhile, despite the inaccuracies, I'm pleased to see the company commemorate Maria Gaetana Agnesi. Perhaps I can locate a bottle of the brandy to drink a toast in honor of her birthday today!


Saturday, October 27, 2018

The "Witch of Agnesi"

Back in 2014, I shared a post about an animated Google Doodle in honor of Maria Gaetana Agnesi's birthday that year.The Doodle appears to represent a curve that bears the odd name "witch of Agnesi." Many books and websites say Maria "invented" the curve, but that's a myth. While Maria does discuss the curve in the mathematics textbook she wrote, the fact is that the curve had already been studied by other mathematicians before her. One of those mathematicians, Guido Grandi, had used the term versiera to describe it.

The name "Witch of Agnesi" was invented by Cambridge University mathematics professor John Colson when he translated Maria's math textbook from Italian into English. Colson gave the book it's English title: Analytical Institutions. Unfortunately, when Colson translated Maria's description of the curve, he apparently confused “la versiera” with “l’avversiera,” which means “wife of the devil.” Because of this mistake, Colson named the curve the “Witch of Agnesi” and that's how it's been known ever since. 

Maria, who was devoutly religious, would be horrified at the name!

Wednesday, May 16, 2018

Celebrating Maria Gaetana Agnesi's 300th Birthday!

May 16, 2018 is the 300th birthday of mathematician-turned-humanitarian Maria Gaetana Agnesi. But Milan, Italy, her birthplace, has special events planned in her honor all year long, including a  program sponsored by Poleticnico Milano on April 19. If you can read Italian, check out the impressive program here

Since my research into Maria Gaetana Agnesi's life led me to write the novel Playing by Heart, inspired by her and her younger sister, Maria Teresa Agnesi, I think it only appropriate to sponsor a giveaway of the novel to celebrate this momentous birthday. See my website for details.

I hope that by Maria Gaetana Agnesi's next birthday, I will have found a publisher for the biography I'm working on about her. Meanwhile, happy birthday, Maria!